Surgical Correction of Hematoma of the Penis in Bulls

Abstract

Rupture of the tunica albuginea of the penis of bulls occurs at a very predictable location, i.e., on the dorsal aspect of the distal bend of the sigmoid flexure (7). The rupture probably occurs as a result of extreme bending of the erect penis during an inept copulatory thrust. The location of the rupture has been described as the point at which a fulcrum (the preputial orifice) is applied to the erect penis (5). However, experimental rupture of 25 cadaver penises with hydraulic pressure at the predicted site with or without bending indicated an intrinsic weakness at the rupture site (3). The tunica albuginea has been described as focally thinner at this point ( 4). The angioarchitecture of the distal bend of the sigmoid flexure with its relatively large cavernous spaces (1) may also contribute to the predisposition. The force for the rupture comes from within the corpus cavernosum penis (CCP) and may be facilitated by the proposed bending. Whereas normal copulatory CCP pressure frequently reaches 200-400 lbs. per sq. in. (psi) (2), the pressure required for the rupture of cadaver penises was ca. 1486 psi (3). At rupture a jet of blood under this pressure serves as a highly traumatic force, which accounts for the severity of the lesions encountered on surgical exposure. The blood tears and displaces the surrounding elastic tissue layers and collects en masse along variable planes of the elastic tissue. The blood may invade the sheaths of the retractor penis muscles. The sensory nerves and vessels dorsal to the penis are vulnerable to injury. The resultant hematoma formation in the excavated surrounding tissue gives the clinical condition its popular name.